Hypergolic igniter for solid motors



Nov. 24, 1970 E. D. MORRIS HYPERGOLIC IGNITER FOR SOLID MOTO S Filed.Sept. 30, 1968 M 8 m A 4. 3 2 J 3 I/ 2 0 /&// 4 .1. r 8 M M/ /4 2 2 3 62 MN m C, M

ATTORNEY US. Cl. 60-256 3 Claims ABSTRACT OF THE DISCLOSURE A hypergolicigniter for solid fuel rocket motors includes a container for ahypergolic fluid, the container having an outlet communicating with achamber containing the solid fuel, the outlet being normally closed by aclosure member fitted thereon. Resilient means urge the closure memberto an open position, and a cable means extends within the container andis connected between the closure member and a retainer means fornormally holding the closure member in a closed position. In oneembodiment, the retainer means is an electrically-actuable, explosivecable cutter which is operable to release the cable means for permittingthe closure members to be moved, by the resilient means, to the openposition.

This invention relates to ignition means for solid rocket motors and isparticularly directed to hypergolic ignition means including a confinedfluid which, when released, reacts chemically with the propellant toignite the rocket motor.

In rocket motors, it is important that ignition of the propellant takeplace with certainty and occur smoothly. Because of this, hypergolicfluids have been preferred as ignition materials over such substances asblack powder. Such fluids are normally inactive, when confined; but,when released, react exothermally with air or the propellant material orboth to cause ignition of the propellant. Numerous means have beenproposed heretofore for confining hypergolic fluids for this purpose.However, none of the prior art techniques have been entirelysatisfactory. Some of the prior art devices have been complicated andunreliable. Other prior art devices have employed easily-removableclosure means, such as frictionally-retained caps, which may be removedsurruptitiously or accidentally during handling causing prematureignition of the propellant material and possibly resulting in seriousdamage and injury.

These disadvantages of the prior art are overcome with the presentinvention and hypergolic ignition means are provided which are simpleand reliable, yet preclude inadvertent release of the hypergolic fluid.

The advantages of the present invention are preferably attained byconfining the hypergolic fluid in a container having a closure memberwhich is spring-biased to an open position but which is normallyretained in a closed position by a cable secured by anelectrically-detonated, explosive, cable-cutting device locatedexternally of said container; and providing expendable support means formounting said container in the throat of a rocket nozzle.

Accordingly, it is an object of the present invention to provideimproved ignition means for solid rocket motors.

Another object of the present invention is to provide ignition means forsolid rocket motors which precludes inadvertent release of the ignitionmaterial.

A further object of the present invention is to provide an improvedcontainer and mounting means for retaining hypergolic fluid for ignitionof solid rocket motors.

These and other objects and features of the present in- States Patent3,541 ,796 Patented Nov. 24, 1970 lice vention will be apparent from thefollowing detailed description taken with reference to the accompanyingdrawing.

In the drawing:

The single figure is a transverse section showing an ignition meansembodying the present invention mounted in the throat of a rocketnozzle.

In that form of the present invention chosen for purposes ofillustration, the drawing shows a rocket motor 2 lined with propellantmaterial 4 and having a nozzle 6 formed with a throat 8. A container 10,formed of any suitable material, is mounted in the throat 8 by mountingmeans 12 formed of a material which can readily be consumed by heat orbe discharged upon ignition of the rocket motor. It has been found thatfoamed polystyrene is admirably suited for this purpose. The container10 is formed with a neck 14 provided with a discharge opening 16 and hasa hollow boss 18 located centrally of the container 10 and extending thefull length thereof. The end of boss 18 adjacent opening 16 is providedwith an enlarged portion 20 formed with an internal shoulder surroundingthe central aperture 24 of boss 18. A closure member, such as cap 26, isformed with a main body 28 covering opening 16 provided with a firstannular flange 30 engaging the neck 14 of container 10 and a secondflange 32 engaging portion 20 of boss 18 to prevent leakage of fluidfrom within container 10. The cap 26 is normally retained in its closedposition by a cable 34 which is attached to body 28 of cap 26 andextends through aperture 24 of boss 18 to an electrically-actuableexplosive, cable cutter 36 which bears against the closed end ofcontainer 10 and is connected by conductors 38 to a suitable actuatingsource, not shown. Finally a spring 40 is disposed within the enlargedportion 20 of boss 18 and is compressed between body 28 of cap 26 andshoulder 22 of boss 18 to urge cap 26 outwardly.

In operation container 10 is filled with hypergolic igniter fluid,preferably under pressure. Cap 26-is secured in its closed position bycable 34 and cable cutter 36 to provide a sealed unit which isspill-proof and tamperproof. Obviously, if desired, this sealed unit maybe employed, with or without mounting means 12, for handling andshipping of the hypergolic fluid and for other similar purposes. Thissealed unit is mounted in the throat 8 of rocket motor 2 by mountingmeans 12 and electrical conductors 38 are connected to the cable cutter36. To ignite the rocket motor 2, an electrical signal is applied viaconductors 38 to fire the cable cutter 36. This severs cable 34,allowing spring 40 to force cap 26 open, releasing the hypergolicigniter fluid to flow through opening 16 to ignite the propellantmaterial 4. Upon ignition of the propellant material 4, the resultingheat and pressure will cause mounting means 12 and container 10 to beconsumed and discharged from the throat 8.

Obviously numerous variations and modifications may be made withoutdeparting from the present invention. Accordingly, it should be clearlyunderstood that the form of the invention described above and shown inthe accompanying drawing is illustrative only and is not intended tolimit the scope of the invention.

What is claimed is:

1. Container means for hypergolic fluids, said container meanscomprising:

a container having a neck and formed with a hollow boss projectinginwardly from the side of said container opposite said neck;

a closure member engageable with said neck and said boss to preventfluid leakage from said container;

resilient means urging said closure means to an open position;

cable means connected to said closure means and extending through saidboss; and

retainer means releasably engaging said cable means and the exterior ofsaid container to normally secure said cable and said closure means in aclosed position.

2. The device of claim 1 wherein:

said retainer-means is an electrically-actuable, explosive, cablecutter.

3. The device of claim 1, further comprising:

heat consumable means for mounting said container in the throat of asolid rocket engine.

References Cited UNITED STATES PATENTS 2,974,484 3/1961 Cooley.3,224,628 12/1965 Emigh et al. 220-47 3,254,603 6/ 1966 Gould 60256 XR3,461,672 8/1969 Harris et al. 60256 CARLTON R. CROYLE, Primary ExaminerUS. Cl. X.R.

